* rename pkg/linksharing to linksharing
* rename pkg/httpserver to linksharing/httpserver
* rename pkg/eestream to uplink/eestream
* rename pkg/stream to uplink/stream
* rename pkg/metainfo/kvmetainfo to uplink/metainfo/kvmetainfo
* rename pkg/auth/signing to pkg/signing
* rename pkg/storage to uplink/storage
* rename pkg/accounting to satellite/accounting
* rename pkg/audit to satellite/audit
* rename pkg/certdb to satellite/certdb
* rename pkg/discovery to satellite/discovery
* rename pkg/overlay to satellite/overlay
* rename pkg/datarepair to satellite/repair
* add voucher service on storage node
* config field tag syntax, go routines for requests
* hook up voucher service in storagenode/peer.go
* add voucher config to testplanet
* add voucher config to testplanet
* add voucher response status INVALID, ACCEPTED, REJECTED
* add a test for vouchers service
* handle no row from GetValid, test it
* add trust pool to voucher service
* use trusted list to get satellites
* verify vouchers upon receipt
* test VerifyVoucher
